JP2022132699A - Curable resin and method for producing the same, curable resin composition and cured product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cured product having heat resistance and excellent dielectric characteristics (low dielectric characteristics) using a curable resin having a specific structure and to provide a method for producing the curable resin.

SOLUTION: There is used a production method in which an aralkyl compound represented by the general formula (3-1) or the general formula (3-2), a phenol represented by the general formula (4) or a derivative thereof, one aralkyl compound and one crosslinking group-introducing agent selected from the group consisting of anhydrous acrylic acid, anhydrous methacrylic acid, acrylic acid chloride, methacrylic acid chloride, chloromethylstyrene, chlorostyrene, allyl chloride and allyl bromide are reacted.

SELECTED DRAWING: None

COPYRIGHT: (C)2022,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a curable resin having a specific structure, a curable resin composition containing the curable resin, and a cured product obtained from the curable resin composition.

With the recent increase in the amount of information communication, information communication in high frequency bands has become popular. There is a need for electrical insulating materials with low dielectric loss tangents.

In addition, printed circuit boards and electronic parts that use these electrical insulating materials are exposed to high-temperature solder reflow during mounting, so materials with excellent heat resistance and a high glass transition temperature are in demand. From the point of view of the problem, the use of lead-free solder with a high melting point has increased the demand for more heat-resistant electrical insulating materials.

To meet these demands, vinyl group-containing curable resins having various chemical structures have been proposed. As such a curable resin, for example, curable resins such as bisphenol divinylbenzyl ether and novolac polyvinylbenzyl ether have been proposed (see, for example, Patent Documents 1 and 2). However, these vinyl benzyl ethers cannot give a cured product with sufficiently low dielectric properties, and the resulting cured product has a problem in stable use in a high frequency band. However, it cannot be said that the heat resistance is sufficiently high.

Several polyvinyl benzyl ethers having specific structures have been proposed in order to improve the dielectric properties and the like of vinyl benzyl ethers having improved properties as described above (see, for example, Patent Documents 3 to 5). Attempts have been made to suppress the dielectric loss tangent and to improve the heat resistance.

Thus, conventional vinyl group-containing curable resins containing polyvinyl benzyl ether can withstand low dielectric loss tangent and lead-free soldering required for electrical insulating material applications, especially for high-frequency electrical insulating material applications. It did not give a cured product having heat resistance.

JP-A-63-68537 JP-A-64-65110 Japanese Patent Publication No. 1-503238 JP-A-9-31006 JP-A-2005-314556

Therefore, the problem to be solved by the present invention is to provide a cured product excellent in heat resistance (high glass transition temperature) and low dielectric properties by using a curable resin having a specific structure. .

Therefore, in order to solve the above problems, the present inventors have made intensive studies, and found that a curable resin that can contribute to heat resistance and low dielectric properties, and a curable resin composition containing the curable resin The inventors have found that the resulting cured product is excellent in heat resistance and low dielectric properties, and have completed the present invention.

That is, the present invention is a curable resin characterized by having a structural unit (1) represented by the following general formula (1) and a terminal structure (2) represented by the following general formula (2) Regarding.

(In general formulas (1) and (2) above, each R ₁ independently represents an alkyl group, aryl group, aralkyl group, or cycloalkyl group having 1 to 12 carbon atoms, and k is 1 to 3. Each R ₂ independently represents a hydrogen atom or a methyl group, X represents a (meth)acryloyloxy group, a vinylbenzyl ether group, or an allyl ether group. In formula (2), each R ₃ independently represents an alkyl group, aryl group, aralkyl group, cycloalkyl group, or alkenyl group having 1 to 12 carbon atoms.)

In the curable resin of the present invention, the above general formula (1) is preferably represented by the following general formula (1-1).

In the curable resin of the present invention, the above general formula (2) is preferably represented by the following general formula (2-1).

(In general formula (2-1) above, R ₄ represents a hydrogen atom, a methyl group, or a phenyl group, and R ₅ represents an alkyl group having 1 to 4 carbon atoms.)

In the curable resin of the present invention, the general formula (1) is represented by the following general formula (1-2), and the general formula (2) is the following general formula (2-2) or (2- 3) is preferably represented.

(In general formulas (1-2), (2-2), and (2-3) above, R ₆ is each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl group , or represents a cycloalkyl group.)

The curable resin of the present invention preferably has a weight average molecular weight of 500 to 50,000.

The present invention relates to a curable resin composition containing the curable resin.

The present invention relates to a cured product obtained by subjecting the curable resin composition to a curing reaction.

Since the curable resin of the present invention can contribute to heat resistance and low dielectric properties, the cured product obtained from the curable resin composition containing the curable resin has heat resistance and low dielectric properties (especially (low dielectric loss tangent) and useful.

The present invention will be described in detail below.

<Curable resin>
The present invention relates to a curable resin characterized by having a structural unit (1) represented by the following general formula (1) and a terminal structure (2) represented by the following general formula (2).

(In the above general formulas (1) and (2), each R ₁ independently represents an alkyl group, an aryl group, an aralkyl group, or a cycloalkyl group having 1 to 12 carbon atoms, and k is 1 to 3 is an integer, each R ₂ independently represents a hydrogen atom or a methyl group, X represents a (meth)acryloyloxy group, a vinylbenzyl ether group, or an allyl ether group, and the general formula (2 ), each R ₃ independently represents an alkyl group, aryl group, aralkyl group, cycloalkyl group, or alkenyl group having 1 to 12 carbon atoms.)

By having the terminal structure and the main chain structure of the curable resin having a specific structure, the proportion of polar functional groups in the structure of the curable resin is reduced, and the curable resin can be used The produced cured product is preferable because it has excellent low dielectric properties. In addition, it is preferable that the curable resin has a cross-linking group, so that the resulting cured product has excellent heat resistance.

In the above general formula (1), each R ₁ independently represents an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl group, or a cycloalkyl group, preferably an alkyl group having 1 to 6 carbon atoms. , an aryl group, or a cycloalkyl group. When R ₁ is an alkyl group having 1 to 12 carbon atoms or the like, the planarity in the vicinity of the benzene ring in the general formula (1) is reduced, and the crystallinity is reduced, thereby improving the solvent solubility. The melting point is lowered, which is a preferred embodiment.

In the above general formula (1), k represents an integer of 1-3, preferably an integer of 1-2. When k is within the above range, the planarity in the vicinity of the benzene ring in the general formula (1) is reduced, and the crystallinity is reduced, improving the solvent solubility and lowering the melting point. Become.

In general formula (1) above, each R ₂ is independently a hydrogen atom or a methyl group. When R ₂ is a hydrogen atom or the like, the dielectric constant is lowered, which is a preferred embodiment.

In general formula (1) above, X is a (meth)acryloyloxy group, a vinylbenzyl ether group, or an allyl ether group, preferably a (meth)acryloyloxy group, more preferably a methacryloyloxy group. is. By having the cross-linking group in the curable resin, a cured product having a low dielectric loss tangent can be obtained, which is a preferred embodiment. In addition, the methacryloyloxy group contains a methyl group in the structure of the curable resin compared to other cross-linking groups (for example, a vinylbenzyl ether group, an ether group that is a polar group such as an allyl ether group). , the steric hindrance is increased, it is assumed that the molecular mobility is further reduced, and a cured product with a lower dielectric loss tangent can be obtained, which is preferable. Moreover, when there are a plurality of cross-linking groups, the cross-linking density is increased and the heat resistance is improved.

In addition, the cross-linking group X is also a polar group, but when the substituent R ₁ is adjacent, it becomes a steric hindrance, the molecular mobility of X is suppressed, and the dielectric loss tangent of the resulting cured product is low. It becomes a preferable mode.

In the above general formula (2), each R ₃ independently represents an alkyl group, aryl group, aralkyl group, cycloalkyl group or alkenyl group having 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms. is an alkyl group, an aryl group, or a cycloalkyl group. When R ₃ is an alkyl group having 1 to 12 carbon atoms or the like, the planarity in the vicinity of the benzene ring in the general formula (2) is lowered, and the crystallinity is lowered, thereby improving the solvent solubility. The melting point is lowered, which is a preferred embodiment. In addition, the cross-linking group X is also a polar group, but when the substituent R ₃ is adjacent, it becomes a steric hindrance, the molecular mobility of X is suppressed, and the dielectric loss tangent of the resulting cured product is low. It becomes a preferable mode.

The curable resin of the present invention is characterized by including the general formulas (1) and (2), has a structure in which the structural unit (1) is repeated, and has a terminal structure based on the general formula (2) However, structures (or structural units) other than the structural unit (1) and the terminal structure (2) include a phenylethylidene skeleton (structure), an indane skeleton (structure), a dicyclopentadiene skeleton (structure), A structure (or structural unit) such as an aralkyl group (structure) having a substituent may be included. That is, the structural unit (1) may form a block structure, or may form a random structure together with other structural units as long as the characteristics of the present invention are not affected. The phenylethylidene skeleton (structure) other than the structural unit (1) and the terminal structure (2) has a small polarity and does not have a structure that increases the dielectric constant or the dielectric loss tangent. does not affect

In the curable resin of the present invention, the above general formula (1) is preferably represented by the following general formula (1-1).

In the curable resin of the present invention, the above general formula (2) is preferably represented by the following general formula (2-1).

In general formula (2-1) above, R ₄ is preferably represented by a hydrogen atom, a methyl group, or a phenyl group, more preferably a hydrogen atom or a methyl group, and R ₅ has the number of carbon atoms. It is preferably represented by an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 to 2 carbon atoms. When R ₄ is the hydrogen atom or the like, the dielectric loss tangent is low, which is a preferable embodiment, and when R ₅ is the alkyl group or the like, the dielectric loss tangent is low, which is a preferable embodiment.

In the curable resin of the present invention, the general formula (1) is represented by the following general formula (1-2), and the general formula (2) is represented by the following general formula (2-2) or (2-3) is preferably represented by

In the general formulas (1-2), (2-2), and (2-3), R ₆ is each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl group, Alternatively, it is preferably represented by a cycloalkyl group, more preferably represented by a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group, or a cycloalkyl group. When R ₆ is the hydrogen atom or the like, the dielectric loss tangent becomes low, which is a preferred embodiment.

In the above general formulas (1) to (2-3), the same symbols, the same substituents, and the same functional groups (k, X, and R ₁ , etc.) are common. shall be The same applies to general formulas (3-1) to (7) described below.

<Method for producing intermediate phenol compound>
As a method for producing the curable resin, first, a method for producing an intermediate phenol compound, which is a raw material (precursor) of the curable resin, will be described below.

As a method for producing the intermediate phenol compound, an aralkyl compound represented by the following general formula (3-1) or (3-2) (hereinafter sometimes referred to as "compound (a)"), and the following general A reaction product (c) obtained by mixing a phenol represented by formula (4) or a derivative thereof (hereinafter sometimes referred to as "compound (b)") and reacting in the presence of an acid catalyst, By reacting an aralkyl compound represented by the following general formula (5-1) or (5-2) (hereinafter sometimes referred to as "compound (d)"), a structural unit represented by the following general formula The intermediate phenol compound having (6) and a terminal structure represented by the following general formula (7) can be obtained.

Moreover, as a method for producing the intermediate phenol compound, it is also possible to prepare the compound (b) and the compound (d) at the same time to synthesize the intermediate phenol compound in one pot.

Y in general formula (3-1) above is preferably a halogen atom, a hydroxyl group, or an oxyalkyl group, more preferably a hydroxyl group.

（３－１）

(3-1)

（３－２）

(3-2)

（４）

(4)

（５－１）

(5-1)

（５－２）

(5-2)

Specific examples of the compound (a) include 1,2-di(chloromethyl)benzene, 1,2-di(bromomethyl)benzene, 1,3-di(chloromethyl)benzene, 1,3-di(fluoro methyl)benzene, 1,4-di(chloromethyl)benzene, 1,4-di(bromomethyl)benzene, 1,4-di(fluoromethyl)benzene, 1,4-di(chloromethyl)-2,5- dimethylbenzene, 1,3-di(chloromethyl)-4,6-dimethylbenzene, 1,3-di(chloromethyl)-2,4-dimethylbenzene, 4,4'-bis(chloromethyl)biphenyl, 2 , 2′-bis(chloromethyl)biphenyl, 2,4′-bis(chloromethyl)biphenyl, 2,3′-bis(chloromethyl)biphenyl, 4,4′-bis(bromomethyl)biphenyl, 4,4′ -bis(chloromethyl)diphenyl ether, 2,7-di(chloromethyl)naphthalene, p-xylylene glycol, m-xylene glycol, 1,4-di(2-hydroxy-2-ethyl)benzene, 4,4' -bis(dimethylol)biphenyl, 2,4'-bis(dimethylol)biphenyl, 4,4'-bis(2-hydroxy-2-propyl)biphenyl, 2,4'-bis(2-hydroxy-2-propyl) biphenyl, 1,4'-di(methoxymethyl)benzene, 1,4'-di(ethoxymethyl)benzene, 1,4'-di(isopropoxy)benzene, 1,4'-di(butoxy)benzene, 1 ,3′-di(methoxymethyl)benzene, 1,3′-di(ethoxymethyl)benzene, 1,3′-di(isopropoxy)benzene, 1,3′-di(butoxy)benzene, 1,4- Di(2-methoxy-2-ethyl)benzene, 1,4-di(2-hydroxy-2-ethyl)benzene, 1,4-di(2-ethoxy-2-ethyl)benzene, 4,4'-bis (Methoxymethyl)biphenyl, 2,4′-bis(methoxymethyl)biphenyl, 2,2′-bis(methoxymethyl)biphenyl, 2,3′-bis(methoxymethyl)biphenyl, 3,3′-bis(methoxy methyl)biphenyl, 3,4'-bis(methoxymethyl)biphenyl, 4,4'-bis(ethoxymethyl)biphenyl, 2,4'-bis(ethoxymethyl)biphenyl, 4,4'-bis(isopropoxy) methylbiphenyl, 2,4′-bis(isopropoxy)methylbiphenyl, bis(1-methoxy-1-ethyl)biphenyl, Bis(1-methoxy-1-ethyl)biphenyl, bis(1-isopropoxy-1-ethyl)biphenyl, bis(2-hydroxy-2-propyl)biphenyl, bis(2-methoxy-2-propyl)biphenyl, bis (2-isopropoxy-2-propyl)biphenyl, 1,3-bis(α-hydroxyisopropyl)benzene, 1,4-bis(α-hydroxyisopropyl)benzene, p-divinylbenzene, m-divinylbenzene, 4, 4′-bis(vinyl)biphenyl, 1,3-bis(1-hydroxyethyl)benzene, 1,4-bis(1-hydroxyethyl)benzene and the like. These compounds (a) may be used alone or in combination of two or more. Among them, as the compound (a), from the viewpoint of industrial availability, for example, p-xylylene glycol, m-xylene glycol, 1,3-bis(α-hydroxyisopropyl)benzene, 1,4 -Bis(α-hydroxyisopropyl)benzene, p-divinylbenzene and m-divinylbenzene are more preferred.

The compound (b) is not particularly limited, but specific examples include cresols such as o-cresol, m-cresol and p-cresol; 2,3-xylenol, 2,4-xylenol and 2,5-xylenol. , 2,6-xylenol (2,6-dimethylphenol), 3,4-xylenol, 3,5-xylenol, 3,6-xylenol; 2,3,5-trimethylphenol, 2,3,6 -trimethylphenol; o-ethylphenol (2-ethylphenol), m-ethylphenol, ethylphenol such as p-ethylphenol; isopropylphenol, butylphenol, butylphenol such as pt-butylphenol; p-pentylphenol, p- Alkylphenols such as octylphenol, p-nonylphenol and p-cumylphenol; monosubstituted phenols such as o-phenylphenol (2-phenylphenol), p-phenylphenol, 2-cyclohexylphenol and 2-benzylphenol; These compounds (b) may be used alone or in combination of two or more. Among them, from the viewpoint of industrial availability, it is more preferable to use, for example, cresol or xylenol as the compound (b). However, if the steric hindrance is too large, there is a concern that the reactivity during the synthesis of the intermediate phenol compound may be inhibited. Therefore, for example, a compound (b) having a methyl group, ethyl group, cyclohexyl group, or phenyl group is used. preferably.

In the method for producing the intermediate phenol compound, the compound (a) and the compound (b) are mixed, and the molar ratio of the compound (b) to the compound (a) (compound (b)/compound (a)) is The compound (a), and A reaction product (c) with the compound (b) can be obtained.

The acid catalyst used in the reaction includes, for example, inorganic acids such as phosphoric acid, hydrochloric acid and sulfuric acid, organic acids such as oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid and fluoromethanesulfonic acid, activated clay, Acid clay, silica alumina, zeolite, solid acids such as strongly acidic ion exchange resins, heteropolyacid salts, etc. can be mentioned, but they are homogeneous catalysts that can be easily removed by neutralization with a base and washing with water after the reaction. Certain oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, fluoromethanesulfonic acid are preferably used.

The amount of the acid catalyst blended is in the range of 0.001 to 40 parts by mass with respect to the total amount of 100 parts by mass of the compound (a) and the compound (b) as raw materials initially charged, 0.001 to 25 parts by mass is preferable from the point of handleability and economy.

The reaction temperature may generally be in the range of 80 to 200° C., but in order to suppress the formation of isomer structures, avoid side reactions such as thermal decomposition, and obtain a high-purity intermediate phenol compound, the temperature should be 100 ~150°C is preferred.

As for the reaction time, if the reaction time is short, the reaction does not proceed completely, and if the reaction time is long, side reactions such as thermal decomposition of the product occur. 0.5 to 24 hours, preferably 0.5 to 15 hours in total.

Specific examples of the compound (d) (which functions as a terminal blocker) are not particularly limited, but specific examples include styrene, styrene dimer, α-methylstyrene, α-methylstyrene dimer, methylstyrene, vinyltoluene), ethylstyrene, t-butylstyrene and other styrene or styrene derivatives, vinylnaphthalene, vinylbiphenyl, diphenylethylene, 1-octene and the like.

The amount of the compound (d) is blended in the range of 1 to 200 parts by mass with respect to the total amount of 100 parts by mass of the compound (a) and the compound (b) as the raw materials initially charged, From the viewpoint of reactivity, 10 to 100 parts by mass is preferable.

The reaction temperature between the compound (b) and the reaction product (c) is usually in the range of 80 to 200° C., but it is possible to suppress the formation of isomer structures, avoid side reactions such as thermal decomposition, and maintain a high temperature. A temperature of 100 to 150° C. is preferred for obtaining a pure intermediate phenol compound.

As for the reaction time, if the reaction time is short, the reaction does not proceed completely, and if the reaction time is long, side reactions such as thermal decomposition of the product occur. 0.5 to 24 hours, preferably 0.5 to 15 hours in total.

In the reaction between the reaction product (c) and the compound (d), the same acid catalyst as used in the reaction between the compound (a) and the compound (b) can be used. can.

In the method for producing the intermediate phenol compound, since the raw material may also serve as a solvent, other solvents may not necessarily be used, but a solvent may be used. In addition, a method of distilling off a solvent (eg, methanol, etc.) generated during the reaction and then performing the reaction within the above reaction temperature range may be employed.

Examples of the organic solvent used for synthesizing the intermediate phenol compound include ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, cyclohexanone and acetophenone; alcohols such as 2-ethoxyethanol and methanol; Aprotic solvents such as N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, N-methyl-2-pyrrolidone, acetonitrile and sulfolane; cyclic ethers such as dioxane and tetrahydrofuran; esters such as ethyl acetate and butyl acetate; and aromatic solvents such as benzene, toluene and xylene, and these may be used alone or in combination.

The hydroxyl equivalent (phenol equivalent) of the intermediate phenol compound is preferably 100 to 1000 g/eq, more preferably 200 to 500 g/eq, from the viewpoint of heat resistance. The hydroxyl group equivalent (phenol equivalent) of the intermediate phenol compound is calculated by a titration method, and refers to a neutralization titration method according to JIS K0070.

<Method for producing curable resin>
A method for producing the curable resin (introduction of a (meth)acryloyloxy group, a vinylbenzyl ether group, or an allyl ether group into an intermediate phenol compound) will be described below.

The curable resin is added to the intermediate phenol compound in the presence of a basic or acidic catalyst, (meth)acrylic anhydride, (meth)acrylic chloride, chloromethylstyrene, chlorostyrene, allyl chloride, or It can be obtained by a known method such as reaction with allyl bromide or the like (hereinafter sometimes referred to as "compound (e)"). By reacting these, a cross-linking group (X) can be introduced into the intermediate phenol compound, and thermosetting with a low dielectric constant and a low dielectric loss tangent can be obtained, which is a preferred embodiment.

Examples of the (meth)acrylic anhydride for the compound (e) (functioning as a crosslinking group-introducing agent) include acrylic anhydride and methacrylic anhydride. Examples of the (meth)acrylic acid chloride include methacrylic acid chloride and acrylic acid chloride. Examples of chloromethylstyrene include p-chloromethylstyrene and m-chloromethylstyrene. Examples of chlorostyrene include p-chlorostyrene and m-chlorostyrene. Examples of allyl chloride include: Examples include 3-chloro-1-propene, and allyl bromide includes, for example, 3-bromo-1-propene. These may be used alone or in combination. Among them, it is preferable to use methacrylic anhydride and methacrylic acid chloride, which give a cured product with a lower dielectric loss tangent.

Specific examples of the basic catalyst include dimethylaminopyridine, alkaline earth metal hydroxides, alkali metal carbonates, and alkali metal hydroxides. Specific examples of the acidic catalyst include sulfuric acid and methanesulfonic acid. In particular, dimethylaminopyridine is superior in terms of catalytic activity.

As the reaction between the intermediate phenol compound and the compound (e), 1 to 10 mol of the compound (e) is added to 1 mol of the hydroxyl group contained in the intermediate phenol compound, and 0.01 to 0.01 2 mol of a basic catalyst may be added all at once, or may be added gradually at a temperature of 30 to 150° C. for 1 to 40 hours.

In addition, by using an organic solvent in combination with the compound (e) (introduction of a cross-linking group), the reaction rate in synthesizing the curable resin can be increased. Examples of such organic solvents include, but are not limited to, ketones such as acetone and methyl ethyl ketone; alcohols such as methanol, ethanol, 1-propyl alcohol, isopropyl alcohol, 1-butanol, secondary butanol and tertiary butanol; cellosolves such as cellosolve and ethyl cellosolve; ethers such as tetrahydrofuran, 1,4-dioxane, 1,3-dioxane and diethoxyethane; aprotic polar solvents such as acetonitrile, dimethylsulfoxide and dimethylformamide; be done. These organic solvents may be used alone, or two or more of them may be used in combination to adjust the polarity.

After the completion of the reaction (introduction of the cross-linking group) with the compound (e) described above, the reaction product is reprecipitated in a poor solvent, and then the precipitate is treated with a poor solvent at a temperature of 20 to 100 ° C. to 0.1 to After stirring for 5 hours and filtering under reduced pressure, the precipitate is dried at a temperature of 40 to 80° C. for 1 to 10 hours to obtain the desired curable resin. Hexane etc. are mentioned as a poor solvent.

The curable resin of the present invention is characterized by including the general formulas (1) and (2), has a structure in which the structural unit (1) is repeated, and is based on the general formula (2) Although it is preferably a terminal structure, due to the above production method, even if a structure other than these structural units (1) and terminal structure (2) is included as a side reaction, the properties of the curable resin in the present invention are not affected. If it's nothing to give, there's no particular problem.

The curable resin of the present invention preferably has a weight average molecular weight (Mw) of 500 to 50,000, more preferably 500 to 20,000, even more preferably 800 to 10,000. It is preferable that the weight-average molecular weight of the curable resin is within the above range because workability and moldability are excellent.

The softening point of the curable resin is preferably 150°C or less, more preferably 50 to 100°C. When the softening point of the curable resin is within the above range, it is preferable because the workability is excellent.

<Curable resin composition>
The curable resin composition of the present invention preferably contains the curable resin. The curable resin has a substituent R ₁ in its structure and —C(CH ₃ )R ₃ R ₃ in its terminal structure, thereby suppressing the molecular mobility of the cross-linking group and providing excellent low dielectric loss tangent. , In addition, by having -CR ₂ R ₂ -C ₆ H ₄ -CR ₂ R ₂ - in the structural unit, the free volume is small, the dielectric constant is excellent, the flexibility is expressed, and the solvent solubility is good. The curable resin composition is easy to prepare, has excellent handling properties, and has a low ratio of polar functional groups in the structure of the curable resin. It is excellent in low dielectric properties and is a preferred embodiment.

[Other resins, etc.]
In the curable resin composition of the present invention, in addition to the curable resin, other resins, curing agents, curing accelerators, and the like can be used without particular limitation within a range that does not impair the object of the present invention. As will be described later, the curable resin can be cured by heating or the like without adding a curing agent. etc. can be mixed and used.

The curable resin composition of the present invention contains the curable resin. Among the curable resins, when X is an allyl ether group, X is a (meth)acryloyloxy group or a vinylbenzyl ether group. Unlike , homopolymerization (crosslinking) cannot be performed (a cured product cannot be obtained by itself), so when X is an allyl ether group, it is necessary to use a curing agent or curing accelerator. .

[Other resins]
Examples of other resins that can be added include alkenyl group-containing compounds such as bismaleimides, allyl ether compounds, allylamine compounds, triallyl cyanurate, alkenylphenol compounds, and vinyl group-containing polyolefin compounds. . Other thermosetting resins such as thermosetting polyimide resins, epoxy resins, phenol resins, active ester resins, benzoxazine resins, cyanate resins, etc. can also be blended appropriately according to the purpose.

[Curing agent]
Examples of the curing agent include amine compounds, amide compounds, acid anhydride compounds, phenol compounds and cyanate ester compounds. These curing agents may be used alone or in combination of two or more.

[Curing accelerator]
Various curing accelerators can be used, and examples thereof include phosphorus compounds, tertiary amines, imidazoles, organic acid metal salts, Lewis acids, and amine complex salts. Particularly when used as a semiconductor encapsulating material, phosphorus compounds such as triphenylphosphine or imidazoles are preferable from the viewpoint of excellent curability, heat resistance, electrical properties, moisture resistance reliability, and the like. These curing accelerators can be used alone or in combination of two or more.

〔Flame retardants〕
If necessary, the curable resin composition of the present invention can be blended with a flame retardant in order to exhibit flame retardancy. Blending is preferred. Examples of the non-halogen flame retardants include phosphorus flame retardants, nitrogen flame retardants, silicone flame retardants, inorganic flame retardants, organic metal salt flame retardants, and the like. More than one type may be used in combination.

〔filler〕
The curable resin composition of the present invention may optionally contain an inorganic filler. Examples of the inorganic filler include fused silica, crystalline silica, alumina, silicon nitride, and aluminum hydroxide. When the amount of the inorganic filler compounded is particularly large, it is preferable to use fused silica. The fused silica may be crushed or spherical, but in order to increase the blending amount of fused silica and suppress the increase in the melt viscosity of the molding material, it is better to mainly use spherical fused silica. preferable. Furthermore, in order to increase the blending amount of spherical silica, it is preferable to appropriately adjust the particle size distribution of spherical silica. Moreover, when using the said curable resin composition for applications, such as a conductive paste detailed below, conductive fillers, such as silver powder and copper powder, can be used.

[Other compounding agents]
The curable resin composition of the present invention may optionally contain various compounding agents such as silane coupling agents, release agents, pigments and emulsifiers.

<Cured product>
The cured product of the present invention is preferably obtained by subjecting the curable resin composition to a curing reaction. The curable resin composition is obtained by uniformly mixing the curable resin alone, or by uniformly mixing each component such as the above-described curing agent in addition to the curable resin, in the same manner as in the conventionally known method. It can be easily cured by the method of. Examples of the cured product include molded cured products such as laminates, cast products, adhesive layers, coating films, and films.

Examples of the curing reaction include heat curing and ultraviolet curing reactions. Among them, the heat curing reaction can be easily performed even in the absence of a catalyst. It is effective to add a polymerization initiator such as a phosphine compound or a basic catalyst such as a tertiary amine. Examples include benzoyl peroxide, dicumyl peroxide, azobisisobutyronitrile, triphenylphosphine, triethylamine, imidazoles and the like.

<Application>
Since the cured product obtained from the curable resin composition of the present invention is excellent in heat resistance and low dielectric properties, it can be suitably used for heat-resistant members and electronic members. In particular, it can be suitably used for prepregs, circuit boards, semiconductor sealing materials, semiconductor devices, build-up films, build-up substrates, adhesives, resist materials, and the like. Moreover, it can be suitably used as a matrix resin for fiber-reinforced resins, and is particularly suitable as a highly heat-resistant prepreg. Moreover, since the curable resin contained in the curable resin composition exhibits excellent solubility in various solvents, it can be made into a coating. The heat-resistant members and electronic members obtained in this way can be suitably used for various applications, for example, industrial machine parts, general machine parts, automobile/railroad/vehicle parts, aerospace-related parts, electronic/electrical parts, Building materials, containers/packaging members, daily necessities, sports/leisure goods, housing members for wind power generation, etc., but not limited to these.

Hereinafter, the present invention will be specifically described with reference to examples and comparative examples, and "parts" and "%" are based on mass unless otherwise specified. A curable resin and a cured product obtained using the curable resin were synthesized under the following conditions, and the obtained cured product was measured and evaluated under the following conditions.

<GPC measurement (evaluation of weight average molecular weight (Mw) of curable resin)>
The GPC chart of the curable resin obtained by the synthesis method shown below was obtained using the following measuring apparatus and measurement conditions. The weight average molecular weight (Mw) of the curable resin was calculated from the results of the GPC chart.

Measuring device: "HLC-8320 GPC" manufactured by Tosoh Corporation
Column: guard column "HXL-L" manufactured by Tosoh Corporation + "TSK-GEL G2000HXL" manufactured by Tosoh Corporation + "TSK-GEL G2000HXL" manufactured by Tosoh Corporation + "TSK-GEL G3000HXL" manufactured by Tosoh Corporation + Tosoh Corporation Made by "TSK-GEL G4000HXL"
Detector: RI (differential refractometer)
Data processing: "GPC Workstation EcoSEC-WorkStation" manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40°C
Developing solvent Tetrahydrofuran
Flow rate 1.0 ml/min Standard: The following monodisperse polystyrene having a known molecular weight was used in accordance with the measurement manual of the "GPC Workstation EcoSEC-WorkStation".

(Polystyrene used)
"A-500" manufactured by Tosoh Corporation
"A-1000" manufactured by Tosoh Corporation
"A-2500" manufactured by Tosoh Corporation
"A-5000" manufactured by Tosoh Corporation
"F-1" manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
"F-4" manufactured by Tosoh Corporation
"F-10" manufactured by Tosoh Corporation
"F-20" manufactured by Tosoh Corporation
"F-40" manufactured by Tosoh Corporation
"F-80" manufactured by Tosoh Corporation
"F-128" manufactured by Tosoh Corporation
Sample: A tetrahydrofuran solution of 1.0% by mass in terms of solid content of the curable resin obtained in Synthesis Example filtered through a microfilter (50 μl).

(Example 1)
324.4 g of o-cresol, 276.3 g of p-xylylene glycol, and p-toluenesulfonic acid monohydrate were placed in a 3 L, 4-neck separable flask equipped with a stirrer, condenser, nitrogen inlet tube, and thermometer. 19.0 g was charged, heated to 150° C. with stirring, and reacted for 5 hours. During this time, methanol produced by the reaction was removed from the system. Then, the temperature was lowered to 120° C., and 260.4 g of styrene was added dropwise over 5 hours for reaction to obtain an intermediate phenol compound.

10.0 g of the intermediate phenol compound synthesized above, 10.0 g of N,N-dimethylformamide, 4-chloromethylstyrene were placed in a 100 mL, 4-necked flask equipped with a stirrer, condenser, nitrogen inlet tube, and thermometer. 9.2 g and 7.0 g of a 48% potassium hydroxide aqueous solution were added, and the temperature was raised to 60° C. while stirring, and the reaction was allowed to proceed for 20 hours. The reaction solution was poured into 100 g of methanol to reprecipitate the polymer. The polymer was redissolved in 100 g of tetrahydrofuran and poured into 100 g of methanol again to reprecipitate the polymer. The resulting polymer was washed twice with 100 g of methanol. Then, it was dried at 50° C. under reduced pressure for 2 hours to obtain a curable resin (Mw: 2100).

(Example 2)
324.4 g of o-cresol, 388.5 g of 1,3-bis(α-hydroxyisopropyl)benzene, and p- 19.0 g of toluenesulfonic acid monohydrate was charged, heated to 150° C. with stirring, and reacted for 5 hours. During this time, water produced by the reaction was removed from the system. Then, the temperature was lowered to 120° C., and 260.4 g of styrene was added dropwise over 5 hours for reaction to obtain an intermediate phenol compound.

10.0 g of the intermediate phenol compound synthesized above, 10.0 g of N,N-dimethylformamide, 4-chloromethylstyrene were placed in a 100 mL, 4-necked flask equipped with a stirrer, condenser, nitrogen inlet tube, and thermometer. 9.2 g and 7.0 g of a 48% potassium hydroxide aqueous solution were added, and the temperature was raised to 60° C. while stirring, and the reaction was allowed to proceed for 20 hours. The reaction solution was poured into 100 g of methanol to reprecipitate the polymer. The polymer was redissolved in 100 g of tetrahydrofuran and poured into 100 g of methanol again to reprecipitate the polymer. The resulting polymer was washed twice with 100 g of methanol. Then, it was dried at 50° C. under reduced pressure for 2 hours to obtain a curable resin (Mw: 2200).

(Example 3)
324.4 g of o-cresol, 332.4 g of 1,4-bis(1-hydroxyethyl)benzene, and p- 19.0 g of toluenesulfonic acid monohydrate was charged, heated to 150° C. with stirring, and reacted for 5 hours. During this time, water produced by the reaction was removed from the system. Then, the temperature was lowered to 120° C., and 260.4 g of styrene was added dropwise over 5 hours for reaction to obtain an intermediate phenol compound.

10.0 g of the intermediate phenol compound synthesized above, 10.0 g of N,N-dimethylformamide, 4-chloromethylstyrene were placed in a 100 mL, 4-necked flask equipped with a stirrer, condenser, nitrogen inlet tube, and thermometer. 9.2 g and 7.0 g of a 48% potassium hydroxide aqueous solution were added, and the temperature was raised to 60° C. while stirring, and the reaction was allowed to proceed for 20 hours. The reaction solution was poured into 100 g of methanol to reprecipitate the polymer. The polymer was redissolved in 100 g of tetrahydrofuran and poured into 100 g of methanol again to reprecipitate the polymer. The resulting polymer was washed twice with 100 g of methanol. Then, it was dried at 50° C. under reduced pressure for 2 hours to obtain a curable resin (Mw: 2200).

(Example 4)
Synthesis was carried out in the same manner as in Example 3 except that 260.4 g of styrene in Example 3 was changed to 295.5 g of α-methylstyrene to obtain a curable resin (Mw: 2000).

(Example 5)
Synthesis was carried out in the same manner as in Example 3 except that 260.4 g of styrene in Example 3 was changed to 295.5 g of 4-methylstyrene to obtain a curable resin (Mw: 1900).

(Example 6)
Synthesis was carried out in the same manner as in Example 3 except that 260.4 g of styrene in Example 3 was changed to 450.8 g of 1,1-diphenylethylene to obtain a curable resin (Mw: 1900).

(Example 7)
Synthesis was carried out in the same manner as in Example 3 except that 260.4 g of styrene in Example 3 was changed to 280.6 g of 1-octene to obtain a curable resin (Mw: 1800).

(Example 8)
Synthesis was carried out in the same manner as in Example 3 except that 324.4 g of o-cresol in Example 3 was changed to 366.5 g of 2-ethylphenol to obtain a curable resin (Mw: 1800).

(Example 9)
Synthesis was carried out in the same manner as in Example 3 except that 324.4 g of o-cresol in Example 3 was changed to 510.6 g of 2-phenylphenol to obtain a curable resin (Mw: 1800).

(Example 10)
Synthesis was carried out in the same manner as in Example 3 except that 324.4 g of o-cresol in Example 3 was changed to 528.8 g of 2-cyclohexylphenol to obtain a curable resin (Mw: 1900).

(Example 11)
Synthesis was carried out in the same manner as in Example 3 except that 324.4 g of o-cresol in Example 3 was changed to 324.4 g of p-cresol to obtain a curable resin (Mw: 2600).

(Example 12)
Example 3 except that 9.2 g of 4-chloromethylstyrene in Example 3 was changed to 9.3 g of methacrylic anhydride, and 7.0 g of 48% potassium hydroxide aqueous solution was changed to 0.2 g of 4-dimethylaminopyridine. Synthesis was carried out in the same manner as in 3 to obtain a curable resin (Mw: 2200).

(Example 13)
324.4 g of o-cresol and 19.0 g of p-toluenesulfonic acid monohydrate were charged in a 3 L, 4-necked separable flask equipped with a stirrer, condenser, nitrogen inlet tube, and thermometer, and the mixture was stirred at 120°C. C., and 280.4 g of divinylbenzene was added dropwise over 5 hours for reaction. After that, 260.4 g of styrene was added dropwise over 5 hours and reacted to obtain an intermediate phenol compound.

10.0 g of the intermediate phenol compound synthesized above, 10.0 g of N,N-dimethylformamide, 4-chloromethylstyrene were placed in a 100 mL, 4-necked flask equipped with a stirrer, condenser, nitrogen inlet tube, and thermometer. 9.2 g and 7.0 g of a 48% potassium hydroxide aqueous solution were added, and the temperature was raised to 60° C. while stirring, and the reaction was allowed to proceed for 20 hours. The reaction solution was poured into 100 g of methanol to reprecipitate the polymer. The polymer was redissolved in 100 g of tetrahydrofuran and poured into 100 g of methanol again to reprecipitate the polymer. The resulting polymer was washed twice with 100 g of methanol. Then, it was dried at 50° C. under reduced pressure for 2 hours to obtain a curable resin (Mw: 2100).

(Example 14)
Synthesis was carried out in the same manner as in Example 3 except that 324.4 g of o-cresol in Example 3 was changed to 366.49 g of 2,5-xylenol to obtain a curable resin (Mw: 2300).

(Example 15)
Synthesis was carried out in the same manner as in Example 3 except that 324.4 g of o-cresol in Example 3 was changed to 408.54 g of 2,3,5-trimethylphenol, and a curable resin (Mw: 2500) was prepared. Obtained.

(Example 16)
The same method as in Example 3 except that 9.2 g of 4-chloromethylstyrene in Example 3 was changed to 7.3 g of acrylic bromide and 7.0 g of 48% potassium hydroxide aqueous solution was changed to 20.0 g of potassium carbonate. to obtain a curable resin (Mw: 1800).

(Comparative example 1)
282.3 g of phenol, 276.3 g of p-xylylene glycol, and 19.5 g of p-toluenesulfonic acid monohydrate were placed in a 3 L, 4-neck separable flask equipped with a stirrer, condenser, nitrogen inlet tube, and thermometer. 0 g was charged, heated to 150° C. with stirring, and reacted for 5 hours. During this time, methanol produced by the reaction was removed from the system to obtain an intermediate phenol compound.

10.0 g of the intermediate phenol compound synthesized above, 10.0 g of N,N-dimethylformamide, 4-chloromethylstyrene were placed in a 100 mL, 4-necked flask equipped with a stirrer, condenser, nitrogen inlet tube, and thermometer. 9.2 g and 7.0 g of a 48% potassium hydroxide aqueous solution were added, and the temperature was raised to 60° C. while stirring, and the reaction was allowed to proceed for 20 hours. The reaction solution was poured into 100 g of methanol to reprecipitate the polymer. The polymer was redissolved in 100 g of tetrahydrofuran and poured into 100 g of methanol again to reprecipitate the polymer. The resulting polymer was washed twice with 100 g of methanol. Then, it was dried at 50° C. under reduced pressure for 2 hours to obtain a curable resin (Mw: 2300).

(Comparative example 2)
324.4 g of o-cresol, 276.3 g of p-xylylene glycol, and p-toluenesulfonic acid monohydrate were placed in a 3 L, 4-neck separable flask equipped with a stirrer, condenser, nitrogen inlet tube, and thermometer. 19.0 g was charged, heated to 150° C. with stirring, and reacted for 5 hours. During this time, methanol produced by the reaction was removed from the system to obtain an intermediate phenol compound.

10.0 g of the intermediate phenol compound synthesized above, 10.0 g of N,N-dimethylformamide, 4-chloromethylstyrene were placed in a 100 mL, 4-necked flask equipped with a stirrer, condenser, nitrogen inlet tube, and thermometer. 9.2 g and 7.0 g of a 48% potassium hydroxide aqueous solution were added, and the temperature was raised to 60° C. while stirring, and the reaction was allowed to proceed for 20 hours. The reaction solution was poured into 100 g of methanol to reprecipitate the polymer. The polymer was redissolved in 100 g of tetrahydrofuran and poured into 100 g of methanol again to reprecipitate the polymer. The resulting polymer was washed twice with 100 g of methanol. Then, it was dried at 50° C. under reduced pressure for 2 hours to obtain a curable resin (Mw: 2400).

<Creation of resin film (cured product)>
The curable resins (solid powders) obtained in Examples and Comparative Examples were placed in a 5 cm square mold, sandwiched between stainless steel plates, and set in a vacuum press. It was pressurized to 1.5 MPa under normal pressure and normal temperature. Next, after reducing the pressure to 10 torr, heating was performed over 30 minutes to a temperature 50° C. higher than the thermosetting temperature. After standing for another 2 hours, it was gradually cooled to room temperature. As a result, a uniform resin film (cured product) having an average thickness of 100 μm was produced.

In Example 16 (where X is an allyl ether group), homopolymerization (crosslinking) of the curable resin alone did not proceed, so only production confirmation of the curable resin was performed, and the following resin films (cured products) were prepared. No evaluation based on

<Evaluation of dielectric properties>
Regarding the in-plane dielectric properties of the obtained resin film (cured product), the dielectric constant and dielectric loss tangent at a frequency of 10 GHz were measured by the split-post dielectric resonator method using a network analyzer N5247A manufactured by Keysight Technologies. was measured. Incidentally, if the dielectric loss tangent is 10×10 ⁻³ or less, there is no practical problem, preferably 5.5×10 ⁻³ or less, more preferably 4.5×10 ⁻³ or less. . Also, if the dielectric constant is 3 or less, there is no practical problem, preferably 2.8 or less, more preferably 2.6 or less.

<Evaluation of heat resistance (glass transition temperature)>
The resulting resin film (cured product) was measured using a PerkinElmer DSC (Pyris Diamond) under the temperature rising condition of 20°C/min from room temperature, and the exothermic peak temperature (thermosetting temperature) observed was measured. After observation, the temperature was maintained at a temperature 50° C. higher than that for 30 minutes. Next, the sample was cooled to room temperature under a temperature decrease condition of 20°C/min, and further heated again under a temperature increase condition of 20°C/min to obtain the glass transition temperature (Tg) (°C) of the resin film (cured product). was measured. A glass transition temperature (Tg) of 100° C. or higher poses no practical problem, and is preferably 130° C. or higher, more preferably 150° C. or higher.

Note) R ₁ in the above Table 1, Examples 1 to 10, 12 and 13 have a methyl group or the like at the ortho position with respect to the bridging group X. Further, Example 11 has a methyl group at the ortho position with respect to the cross-linking group X, and Example 14 has a methyl group at the ortho-position (2-) and meta-position (5-) with respect to the cross-linking group X. and Example 15 has methyl groups at the ortho (2-), meta (3-), and meta (5-) positions relative to the bridging group X.

Note) Ph in Tables 1 and 2 above represents a phenyl group, and Cy represents a cyclohexyl group.

From the evaluation results in Tables 1 and 2 above, in all the examples, the cured product obtained by using the curable resin can achieve both heat resistance and low dielectric properties, and is practically It was confirmed that the level was satisfactory.

On the other hand, from the evaluation results in Table 2 above, in Comparative Example 1, the dielectric loss tangent and the dielectric constant were reduced due to the high molecular mobility of the main chain and terminal cross-linking groups (polar sites) in the obtained curable resin. It was confirmed that the glass transition temperature (Tg) was low and the heat resistance was poor due to the relatively high value, poor dielectric properties (no low dielectric properties were obtained), and low rigidity of the main chain. In Comparative Example 2, due to the high molecular mobility of the cross-linking groups (polar sites) at the ends of the curable resin, the dielectric loss tangent and the dielectric constant show high values, the dielectric properties are poor, and the rigidity of the main chain is low. It was also confirmed that the glass transition temperature (Tg) was low and the heat resistance was poor due to the low heat resistance.

The cured product obtained by using the curable resin of the present invention is excellent in heat resistance and dielectric properties, so that it can be suitably used for heat-resistant members and electronic members. It can be suitably used for substrates, build-up films, build-up substrates, adhesives and resist materials. Moreover, it can be suitably used as a matrix resin for fiber-reinforced resins, and is suitable as a highly heat-resistant prepreg.

Claims (7)

an aralkyl compound represented by the following general formula (3-1) or the following general formula (3-2);
A phenol represented by the following general formula (4) or a derivative thereof,
One selected from the group consisting of styrene, styrene dimer, α-methylstyrene, α-methylstyrene dimer, vinyltoluene, ethylstyrene, t-butylstyrene, vinylnaphthalene, vinylbiphenyl, diphenylethylene, and 1-octene an aralkyl compound;
one crosslinking group introducing agent selected from the group consisting of acrylic anhydride, methacrylic anhydride, acrylic acid chloride, methacrylic acid chloride, chloromethylstyrene, chlorostyrene, allyl chloride, and allyl bromide;
A method for producing a curable resin by reacting the

(3-1)
[In general formula (3-1) above, each R ₂ independently represents a hydrogen atom or a methyl group. Y represents a halogen atom, a hydroxyl group, or an oxyalkyl group. ]

(3-2)

(4)
[In the above general formula (4), each R ₁ independently represents an alkyl group, an aryl group, an aralkyl group, or a cycloalkyl group having 1 to 12 carbon atoms, and k represents an integer of 1 to 3. . ] an aralkyl compound represented by the following general formula (3-1) or the following general formula (3-2);
a reactant obtained by reacting a phenol represented by the following general formula (4) or a derivative thereof;
One selected from the group consisting of styrene, styrene dimer, α-methylstyrene, α-methylstyrene dimer, vinyltoluene, ethylstyrene, t-butylstyrene, vinylnaphthalene, vinylbiphenyl, diphenylethylene, and 1-octene 2. The production method according to claim 1, wherein an aralkyl compound is reacted. The aralkyl compound represented by the general formula (3-1) or (3-2) is 1,2-di(chloromethyl)benzene, 1,2-di(bromomethyl)benzene, 1,3-di(chloromethyl) ) benzene, 1,3-di(fluoromethyl)benzene, 1,4-di(chloromethyl)benzene, 1,4-di(bromomethyl)benzene, 1,4-di(fluoromethyl)benzene, 1,4- Di(chloromethyl)-2,5-dimethylbenzene, 1,3-di(chloromethyl)-4,6-dimethylbenzene, 1,3-di(chloromethyl)-2,4-dimethylbenzene, 4,4 '-bis(chloromethyl)biphenyl, 2,2'-bis(chloromethyl)biphenyl, 2,4'-bis(chloromethyl)biphenyl, 2,3'-bis(chloromethyl)biphenyl, 4,4'- bis(bromomethyl)biphenyl, 4,4'-bis(chloromethyl)diphenyl ether, 2,7-di(chloromethyl)naphthalene, p-xylylene glycol, m-xylene glycol, 1,4-di(2-hydroxy- 2-ethyl)benzene, 4,4'-bis(dimethylol)biphenyl, 2,4'-bis(dimethylol)biphenyl, 4,4'-bis(2-hydroxy-2-propyl)biphenyl, 2,4'- bis(2-hydroxy-2-propyl)biphenyl, 1,4'-di(methoxymethyl)benzene, 1,4'-di(ethoxymethyl)benzene, 1,4'-di(isopropoxy)benzene, 1, 4'-di(butoxy)benzene, 1,3'-di(methoxymethyl)benzene, 1,3'-di(ethoxymethyl)benzene, 1,3'-di(isopropoxy)benzene, 1,3'- Di(butoxy)benzene, 1,4-di(2-methoxy-2-ethyl)benzene, 1,4-di(2-hydroxy-2-ethyl)benzene, 1,4-di(2-ethoxy-2- ethyl)benzene, 4,4'-bis(methoxymethyl)biphenyl, 2,4'-bis(methoxymethyl)biphenyl, 2,2'-bis(methoxymethyl)biphenyl, 2,3'-bis(methoxymethyl) biphenyl, 3,3′-bis(methoxymethyl)biphenyl, 3,4′-bis(methoxymethyl)biphenyl, 4,4′-bis(ethoxymethyl)biphenyl, 2,4′-bis(ethoxymethyl)biphenyl, 4,4'-bis(isopropoxy)methylbiphenyl, 2,4'-bis(isopropoxy)methylbiphenyl, bis(1-meth oxy-1-ethyl)biphenyl, bis(1-methoxy-1-ethyl)biphenyl, bis(1-isopropoxy-1-ethyl)biphenyl, bis(2-hydroxy-2-propyl)biphenyl, bis(2-methoxy -2-propyl)biphenyl, bis(2-isopropoxy-2-propyl)biphenyl, 1,3-bis(α-hydroxyisopropyl)benzene, 1,4-bis(α-hydroxyisopropyl)benzene, p-divinylbenzene , m-divinylbenzene, 4,4′-bis(vinyl)biphenyl, 1,3-bis(1-hydroxyethyl)benzene, and 1,4-bis(1-hydroxyethyl)benzene 3. The production method according to claim 1 or 2, which is one or more aralkyl compounds. The phenol represented by the general formula (4) or a derivative thereof is o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6 -xylenol, 3,4-xylenol, 3,5-xylenol, 3,6-xylenol, 2,3,5-trimethylphenol, 2,3,6-trimethylphenol, o-ethylphenol, m-ethylphenol, p -ethylphenol, isopropylphenol, butylphenol, pt-butylphenol, p-pentylphenol, p-octylphenol, p-nonylphenol, p-cumylphenol, o-phenylphenol (2-phenylphenol), p-phenylphenol, 3. The production method according to claim 1 or 2, wherein the phenol is at least one phenol selected from the group consisting of 2-cyclohexylphenol and 2-benzylphenol, or a derivative thereof. A curable resin comprising a structural unit (1) represented by the following general formula (1) and a terminal structure (2) represented by the following general formula (2).

[In the above general formulas (1) and (2), each R ₁ independently represents an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl group, or a cycloalkyl group, and k is 1 to 3; indicates an integer of . Each R ₂ independently represents a hydrogen atom or a methyl group. X represents a (meth)acryloyloxy group, a vinylbenzyl ether group, or an allyl ether group.
In general formula (2) above, R ₃ represents any combination of a phenyl group and a hydrogen atom, a phenyl group and a methyl group, a phenylmethyl group and a hydrogen atom, a phenyl group and a phenyl group, or a hexyl group and a hydrogen atom. show. ] A curable resin composition containing the curable resin according to claim 5 . A cured product obtained by subjecting the curable resin composition according to claim 6 to a curing reaction.